public IDictionary <ICurrencyDenomination, int> GetChange(PurchaseTransaction transaction, IEnumerable <ICurrencyDenomination> denominationsAvailable)
{
decimal amountChangeDue = transaction.AmountReceived - transaction.AmountOwed;
var changeCalculator = GetCalculator(transaction.AmountOwed);
return(changeCalculator.GetChange(amountChangeDue, denominationsAvailable));
}
public IEnumerable <PurchaseTransaction> GetPurchaseTransactions()
{
List <PurchaseTransaction> purchaseTransactions = new List <PurchaseTransaction>();
using (StreamReader fileStreamReader = File.OpenText(_filePath))
{
int fileLineNumber = 1;
string transactionLine;
while ((transactionLine = fileStreamReader.ReadLine()) != null)
{
// Assume any blank line is the end of the file, so that we can skip any remaining new lines at the end of the file.
if (String.IsNullOrWhiteSpace(transactionLine))
{
break;
}
string[] transactionAmounts = transactionLine.Split(',');
// Check for an incorrect number of parameters for our expected input
if (transactionAmounts.Length != 2)
{
throw new Exception(String.Format(UNEXPECTED_INPUT, transactionLine, fileLineNumber, _filePath));
}
PurchaseTransaction transaction = new PurchaseTransaction();
decimal amountOwed;
decimal amountReceived;
bool amountOwedParseSuccess = Decimal.TryParse(transactionAmounts[0], out amountOwed);
bool amountReceivedParseSuccess = Decimal.TryParse(transactionAmounts[1], out amountReceived);
// Check that the values received are decimal values
if (!amountOwedParseSuccess || !amountReceivedParseSuccess)
{
throw new Exception(String.Format(UNEXPECTED_INPUT, transactionLine, fileLineNumber, _filePath));
}
transaction.AmountOwed = amountOwed;
transaction.AmountReceived = amountReceived;
purchaseTransactions.Add(transaction);
fileLineNumber++;
}
}
return(purchaseTransactions);
}
public string CalculateChange(PurchaseTransaction transaction)
{
string output;
if (transaction.AmountReceived < 0)
{
output = NEGATIVE_RECEIVED_AMOUNT;
}
else if (transaction.AmountReceived > transaction.AmountOwed)
{
IDictionary <ICurrencyDenomination, int> denominationsDue = _changeCalculationStrategy.GetChange(transaction, DenominationsInRegister);
StringBuilder denominationAmountsStringBuilder = new StringBuilder();
foreach (KeyValuePair <ICurrencyDenomination, int> denomination in denominationsDue)
{
int numberOfTheDenomination = denomination.Value;
string denominationName;
if (denomination.Key is UsCurrencyDenomination)
{
UsCurrencyDenomination usCurrencyDenomination = (UsCurrencyDenomination)denomination.Key;
denominationName = numberOfTheDenomination > 1
? usCurrencyDenomination.PluralizedName
: usCurrencyDenomination.Name;
}
else
{
denominationName = denomination.Key.Name;
}
denominationAmountsStringBuilder.Append(numberOfTheDenomination + " " + denominationName + ", ");
}
// Remove trailing comma
output = denominationAmountsStringBuilder.Remove(denominationAmountsStringBuilder.Length - 2, 2).ToString();
}
else if (transaction.AmountReceived == transaction.AmountOwed)
{
output = NO_CHANGE_REQUIRED_MESSAGE;
}
else
{
decimal amountStillDue = transaction.AmountOwed - transaction.AmountReceived;
output = String.Format(INSUFFICIENT_FUNDS_RECEIVED, amountStillDue.ToString("C", NumberFormatInfo.CurrentInfo));
}
return(output);
}
public IDictionary <ICurrencyDenomination, int> GetChange(PurchaseTransaction transaction, IEnumerable <ICurrencyDenomination> denominationsAvailable)
{
var changeCalculator = new LargestDenominationFirstChangeCalculator();
return(changeCalculator.GetChange(transaction.AmountReceived - transaction.AmountOwed, denominationsAvailable));
}
private static void OutputChange(CashRegister cashRegister, PurchaseTransaction transaction)
{
Console.WriteLine(cashRegister.CalculateChange(transaction));
}
